1. Field of the Invention
Embodiments of the present invention relate to the manufacture of devices such as light emitting diodes (LEDs) or laser diodes (LDs). More particularly, embodiments of the present invention relate to apparatus and method for pretreatment of substrates for manufacturing devices such as light emitting diodes (LEDs) or laser diodes (LDs).
2. Description of the Related Art
Group III nitride semiconductors are finding greater importance in the development and fabrication of a variety of semiconductor devices, such as short wavelength light emitting diodes (LEDs), laser diodes (LDs), and electronic devices including high power, high frequency, high temperature transistors and integrated circuits. Light emitting diodes (LEDs) and laser diodes (LDs) are fabricated by depositing group-III nitrides on sapphire substrates. Group-III nitrides can be deposited by hydride vapor phase epitaxy (HYPE), metal organic chemical vapor deposition (MOCVD), chemical vapor deposition (CVD), and/or physical vapor deposition (PVD) on aluminum oxide containing substrates, such as sapphire substrates.
Aluminum oxide containing substrates need to be pretreated before deposition of group-III nitrides to generate low defect density group-III nitride layers. However, traditional methods for treating aluminum oxide containing substrates may leave by-products on walls of reaction chamber, exhaust lines, and pumps contaminating the manufacturing processes and reducing yield of the facility.
Therefore, there is a general need for methods and apparatus for treating aluminum oxide containing substrates with reduced by-product formation.